The dental health of children, adolescents and adults may be affected by fears of dental treatment (~10-30% of patients are afraid of dental treatment). This can be challenging for both the patients and the dental personnel. In the care of patients with fears of dental treatment, inhalation sedation with nitrous oxide (N2O) in the context of anxiety and behavioural management in dentistry is of central importance. The administration of inhalation sedation with N2O in dentistry serves as a minimal or conscious sedation for the patient. N2O has an anxiolytic as well as slight analgesic and sedative effect. According to the Council of European Dentists (CED), inhalation sedation with N2O is a proven and safe method to manage anxiety and pain in dentistry (mainly for anxious and/or very young patients).

Among other aspects, this report deals with questions of organisational and professional issues regarding the administration of inhalation sedation with N2O. In addition, a systematic analysis of the efficacy and safety of inhalation sedation with N2O in dentistry was performed. In order to answer the research questions, a systematic literature search, an additional literature search with Scopus (citation tracking) and targeted manual searches for relevant (professional) guidelines and guiding principles of dentistry on the websites of institutions and professional societies of selected European countries (Germany, Switzerland, Austria, Sweden and the Netherlands) were carried out.

With regard to the underlying research questions on the organisational and professional aspects, it has been shown that inhalation sedation with N2O should be used only by dental personnel, who are appropriately trained in the use of sedation and emergency procedures. When inhalation sedation with N2O is performed by qualified dental personnel, with carefully selected patients, and with appropriate equipment, it is considered to be a safe and effective procedure in primary care to support anxiety and behavioural management according to the CED. The respective national framework conditions must be adapted to the guidelines of the CED.
Regarding the clinical efficacy and safety analysis, ten studies (three randomised controlled trials and seven randomised controlled crossover trials) were identified. The strength of evidence for the endpoints of clinical efficacy and safety was rated as "low" to "very low". None of the included studies for the clinical effectiveness and safety clearly demonstrated that inhalation sedation with N2O is more effective than placebo (O2/room air) or midazolam. However, the data on adverse events suggest that inhalation sedation with N2O is safe in the administration per se and therefore a useful method in dentistry.

In conclusion, inhalation sedation with N2O appears to be a useful and safe procedure in dentistry for the anxiety and behavioural management of children, adolescents, and adults with fears of dental treatment.